http://innovation.uk.msn.com/design/the-3d-printer-that-can-build-a-house-in-24-hours

The University of Southern California is testing a giant 3D printer that could be used to build a whole house in under 24 hours.

Professor Behrokh Khoshnevis has designed the giant robot that replaces construction workers with a nozzle on a gantry, this squirts out concrete and can quickly build a home according to a computer pattern. It is “basically scaling up 3D printing to the scale of building,” says Khoshnevis. The technology, known as Contour Crafting, could revolutionise the construction industry.

Contour Crafting could slash the cost of home-owning, making it possible for millions of displaced people to get on the property ladder. It could even be used in disaster relief areas to build emergency and replacement housing.  For example, after an event such as Typhoon Haiyan in the Philippines, which has displaced almost 600,000 people, Contour Crafting could be used to build replacement homes quickly.

It could be used to create high-quality shelter for people currently living in desperate conditions. “At the dawn of the 21st century [slums] are the condition of shelter for nearly one billion people in our world,” says Khoshnevis, “These buildings are breeding grounds for disease a problem of conventional construction which is slow, labour intensive and inefficient.”

As Khoshnevis points out, if you look around you pretty much everything is made automatically these days – “your shoes, your clothes, home appliances, your car. The only thing that is still built by hand are these buildings.”

The Contour Crafting system is a robot that by automates age-old tools normally used by hand. These are wielded by a robotic gantry that builds a three-dimensional object.

“Ultimately it would work like this,” says Brad Lemley from Discover Magazine. “On a cleared and leveled site, workers would lay down two rails a few feet further apart than the eventual building’s width and a computer-controlled contour crafter would take over from there. A gantry-type crane with a hanging nozzle and a components-placing arm would travel along the rails. The nozzle would spit out concrete in layers to create hollow walls, and then fill in the walls with additional concrete… humans would hang doors and insert windows.”

“It’s a CAD/CAM solution,” says Khoshnevis. The buildings are “designed on computer and built by a computer”. Contour Crafting hopes to generate “entire neighbourhoods built at a fraction of the cost, in a fraction of the time, far more safely, and with architectural flexibility that is unprecedented.”

The Contour Crafting solution also produces much stronger structures than traditional building methods. According to Contour Crafting the tested wall is a 10,000PSI (pounds per square inch) strength compared to an average of 3,000PSI for a regular wall.

What the implications are for builders is, of course, a major concern. Building and construction has largely escaped the construction line automation of other industries and remains solid employment for millions worldwide. According to the International Labour Organisation construction employs nearly 110 million people worldwide and “plays a major role in combating the high levels of unemployment and in absorbing surplus labour from the rural areas.”

That’s a lot of people Contour Crafting could make redundant, which raises the question of whether the system could do more harm than good.

http://innovation.uk.msn.com/design/the-3d-printer-that-can-build-a-house-in-24-hours